More than 1.4 million BMW models in the United States are being recalled due to potential fire hazard.

In a pair of recalls, BMW is set to repair more than 1.4 million vehicles in the United States, which are at risk for a fire hazard stemming from an electrical issue.

The larger of the two recalls involves a malfunction in a heater for the positive crankcase ventilation valve. BMW spokesman Hector Arellano-Belloc said the heater is designed to prevent the valve from freezing in cold temperatures, but irregularities in manufacturing can cause corrosion, which leads to overheating of the component. When overheated, the heater can cause the ventilation valve to melt, increasing the risk of a fire even when the vehicle is parked.

Dealers will replace the heater on approximately 740,000 vehicles built from 2007 to 2011. Affected models include the 1 Series (128i), 3 Series (328i with rear-wheel or all-wheel drive), the 5 Series (525i, 528i, 530i – all with RWD or AWD), X3, X5 (xDrive30i), and Z4.

The other recall is due to faulty wiring for the heating and air conditioning system, which can overheat and cause connectors to melt. This causes fire risk to increase, even when the vehicles are unattended. Dealers will replace wiring and connectors on 2006-2011 3 Series models equipped with gasoline and diesel 6-cylinder engines, as well as the M3 performance model.

Repairs are to begin on December 18th, 2017, and certain 3 Series models are included in both recalls. BMW advises owners of affected vehicles to leave them parked outside “in an abundance of caution.”